What specific resins and hardeners are people using for these bikes? I'm thinking of using West System 105 resin and 205 hardener, would that work?

Also, how much epoxy are we talking here? I assume a 1.2 Kg pack would be sufficient.

I used the 105/205a system, which is the smallest, and I ended up using around 2/3 of the epoxy in total for one bike.

Any of the standard boatbuilding epoxies are adequate. They all seem to claim to be "the best" anyway. MAS, WEST, System Three Silver Tip. I've used them all and you can't really notice any difference.
I think MAS is a bit lower in toxicity of the fumes so that's good if you are going to be working with the stuff extensively.
Boo Bicycles uses WEST.

I've been doing a bit of experimenting with bamboo while I wait for some parts to arrive, and I've found some interesting things. I've been splitting short lengths of bamboo in half and gluing them back together, and have found that this does not seem to decrease the strenth in any way. Once they have been glued, I split them from the inside out, and none of them have cracked along the glue lines. This means that one could split your bamboo tubes in half, apply a protective coating to the inside, and then just glue the two halves back together when you build the frame. I tried using both a diagonal cut, for more surface area, and a cut perpendicular to the outside, and neither broke.

http://img819.imageshack.us/img819/2943/p7200344.jpg
http://img413.imageshack.us/img413/1664/p7200347.jpg

An interesting point this leads to, is the fact that you can then make bladed bamboo tubes, if you have large enough diameter bamboo available:

http://img706.imageshack.us/img706/5006/p7200350.jpg

To maximize surface area on the bladed tube, I cut a right angle in one side, and a notch in the other, as shown:

http://img59.imageshack.us/img59/8273/p7200354.jpg


There is probably very little practical application for bladed tubes, but It would look pretty awesome. If I were to actually do this in a bike, it would probably just be for the down tube.

I did not break the glue joints on any of these, and I was not even using epoxy- I just used regular wood glue.

It's funny how I am not quite even finished with my first bike, and I have already planned out a second one!

It's not surprising that splitting bamboo and gluing it back together doesn't affect the strength. That's because bamboo has little resistance to splitting anyway. Gluing it together would make the glue line the strongest part of the tube.
I've also played around with the aero boo concept.
You don't need to split the tubes to coat the inside with epoxy though. Just punch the nodes out cap one end and partially fill the tube with epoxy, swirl it around to coat the interior and dump out the excess.

While that bamboo is split open, you might as well add a layer or two of carbon fiber to it! :lol:
I might try this on my next one.

My frame is now finished. All I need are the rest of the parts to build it up, and a seatpost clamp. I ended up doing the clear coat with spar varnish.

http://img682.imageshack.us/img682/1129/dscn0524a.jpg

I made a headbadge for it as well, out of a segment of steel tubing:

http://img696.imageshack.us/img696/9937/dscn0511b.jpg

Here's a picture of what I did the design from:

http://img697.imageshack.us/img697/4992/robotab.jpg

Wow she's beautiful congratulations!
I Like the badge.

http://i399.photobucket.com/albums/p...refinish_3.jpg
http://i399.photobucket.com/albums/p...refinish_1.jpg
http://i399.photobucket.com/albums/p.../Prefinish.jpg
http://i399.photobucket.com/albums/p...5/Finish_8.jpg
http://i399.photobucket.com/albums/p...5/Finish_6.jpg
http://i399.photobucket.com/albums/p...5/Finish_5.jpg
http://i399.photobucket.com/albums/p...5/Finish_4.jpg
http://i399.photobucket.com/albums/p...5/Finish_3.jpg
http://i399.photobucket.com/albums/p...5/Finish_2.jpg
http://i399.photobucket.com/albums/p...refinish_4.jpg

Beautiful.

I've fiished some bamboo with boatbuilding epoxy. It sinks in pretty well which surprised me, given the glossy finish of the bamboo itself. A clearcoat would still be required.

Canaboo, that frame is gorgeous. Is there any particular reason you chose to extend the carbon lugs so far onto the bamboo tubes, or do you just like the look?

Does anybody have any experience painting a bamboo frame? What would the process be and what would be the appropriate paint to ensure that it sticks and that it doesn't crack and chip?

Thanks,
Dan

Thanks. The junction where tubes join each other is an area of concentrated stress so feathering the carbon out over a wider area spreads that stress out. Much like filing metal lugs thinner on the edges does the same thing.

I went on a leisurely ride today with a few friends on my bamboo bike. Ironically, the only problem is not with my hand-built frame, but with my front wheel, which has a bulge in the rim. 3 people asked me if my bike was actually made of bamboo. The only thing I have to do now is put in a couple cable stops for the back brake.

Once again nice work!
As you may know I've been working on a bamboo/fiberglass bike and as I approach the final stages of the build, I wonder if the amount of fiber I used is enough.
Can you tell me how many layers of carbon fiber did you use on each lug and on the rear dropouts? And the material you use, it has unidirectional fibers right?!

I can tell you that I made a bike and just sleeved the seat tube and downtube onto the BB shell and applied a single layer of glass tape before I test rode the frame. The rear dropouts were just glued in place. The head tube was done a bit better. I rode the bike really hard over rough roads before I finally cracked the joint at the BB shell while hammering up a steep hill.
That may give you an idea of the minimal amount required.
The bike I just posted has somewhere around 6-10 layers of 6k unidirectional at the major lugs and just 2-3 on the dropouts. It's hard to get an accurate gauge when applying multiple layers because you lose track pretty quickly since the wrapping is fairly erratic in application. I like to spiral it and criss-cross it to get a bit more visual effect.

Does anyone know where I can order tonkin poles? The place I originally got my bamboo from ran out of larger diameter bamboo. I tried placing an order with another site, but the payment has been pending for a while and the site seems to have disappeared now! :eek:

http://www.franksupply.com/
^^^^
These guys are in Huntington Beach and shipped to me in Georgia.
I've been to their shop. They have a warehouse full of poles of different verities.
IIRC the shop owner's name is Mike (Frank is his last name). Nice guy.
Call them up and tell them what size you want and the'll hand pick some nice sticks for you.

Here's my finished and built up bike:

http://a.imageshack.us/img641/4/dscn1064i.jpg

http://a.imageshack.us/img444/1295/dscn1051yb.jpg

http://a.imageshack.us/img534/7295/dscn1050o.jpg

I made bamboo cable stops:

http://a.imageshack.us/img202/6420/dscn1044x.jpg

http://a.imageshack.us/img441/4120/dscn1038y.jpg

It will soon have clipless pedals, and probably a new seat.

How are the cable stops being held on? Is it just epoxy? I tried that before, and when I tried to brake, the cable stops snapped off. :(

I just noticed those are bamboo stops. Nice.

I've also had problems with just epoxying stops.

Are 2" diameter poles the right size for the front triangle?

The larger the diameter the stiffer the tube, but with wood stiffness can vary from stick to stick.
1.5 inch main triangles have been too whippy for me though. Much larger than 2 inches you can be too large for your bottom bracket shell.

Sorry about the non definitive answer but there is no real standard (lots of variability) in a natural product.

That's good enough. Thanks. :)

Yep, the stops are epoxied on, but the brakes have cable housing all the way to them. The rear derailluer has real cable stops, but there is not too much force on them, so I have not had any problems.

You guys have given me a marketing idea: I'm thinking about going to the Chinese people who build Walmart bikes, and having them do a bamboo paint scheme on them. I bet I can beat you to market with an affordable "bamboo" bike!

Okay... I'm just kidding!

Carbon fiber seems to be what most of you use. Can one use just fiberglass or hemp? BTW I can't seem to find hemp tow for sale, any leads on that?

Hemp works quite well.
You won't find hemp tow line per say but you can find hemp fiber.
Google hemp fiber and you'll find tons of sites selling it (mostly weaving sites).

Awesome!